Spooled film



Jne 12, 1934. D. H. KINLOCH SPOOLED FILM Filed Jan. 9 1933 INVENTOR- Donald H. Kinloch BY 'A'IT'ORNEY- atented June 12, 1934 sroouan FILM Donald H. Kinloch,

Parlin, N. J.

assignor to Du Pont Film Manufacturing Corp., New York, N. Y., a corpoxation o! Delaware Application January 9, 1933, Serial N0. 650,781

2 Claims.

'I'his invention relates to means end method for zpooling light-sensitive eine film.

In prior manUfacture, finished lightsensitive :ine film reached the pack1'ng operation as a ;ightly wound roll containing no spool of any sort, md es it was packed, a wooden spool about 1" in 1iameter was insert-ed in the open center of the roll of film. This spool subsequently had to be forced out by the cameraman prior to loading his magazine, and also presented numerous other iisadvantages; the wood splintered and deposited foreign particles on the sensitive surface of the film, and furthermore, a.ny wood used required various Wellknown impregnating treatments such as potassium permanganate or sodium carbonate solutions to reduce its tendency to t'og the lightsensitive em-ulsion on the film. 1't has also been found that similar serious fogging ema.natigns arise not only from wood spools but also from those made 01 compositions of rubber or paper. fibre or wood pulp end also from spools covered with lacquers end varnishes that have been applied to metal end other spools.

The small diameter 015 these spools also caused a considerable length of the film nea.r the center of the roll to curl, which presented subsequent difllculties in use. Several types end ,sizes 01' spools were tried, but with no better }success. Same o1 these spools had slots in the outer surface to engage the end of .the film wound thereon.

A spool in the form of a. steel sleeve was next used, which xe-embodied the original 1" diameter end which was designed to remain in the roll for use in the camera magazine. It was soon fou.nd th.a.t the edges 01 metal spools cut the tabric used tot lining the camera magazlnes, end furl;hermore, such spools were trequently deformed' during shipment 01' handllrig or whenever a. roll 01 film was dropped.

One object; ot' the present invention is to provide a film spool that will not log, or contaminate wlth' l'orelgn matter, the light-sensitive emulsion on a roll of einem film. A further object is to provide a method o1 spoollng' film thal: will fr ee the end portion of the roll from curl end fog re gardless 015 the thickness of the film used. An additional object is to provide a. spool of durable, light weight constructlon that will not be subject to deformation or fracture a.nd that will have no abrasive actlon on the magazines in whlch it is used. Other more speclflc objects will plelnhr appear from the detailed description bresented herein.

I In the drawlnlz fllustrating one embodlment 01' the invention, by way 01 exarriple, Figure 1 represents a. perspective view 01 my improved spool, showing one end of a roll 01 einem film as attached thereto by the camerama.n by means o1 adhesive tape. Figure 2 represents an end view. c of the structure shown in Figure 1. Figure 3 represents a longitudinal cross section taken on the line 33. Figure 4 represents a. transverse cross section taken on the line 4-4 After experimentation with spools of various 6 dimensions a.nd materials end plastic compositions, I found that smooth surfaeed, molded and seasoned spools made of synthetic or artificial resins, preferably from phenol condensation products, such as phenol formaldehyde resins, af-

forded many improved features lang sought without: success in the prior art. A variety of artificial resins may be employed; among these are cresol formalclehyde resins, urea formaldehyde gesins, polyhydric alcohol polybasic acids polystyrol, toluene sulphonamide derivaties plus forma.ldehyde, poly vinyl compounds, and casein compounds. Spools have been molded of cellulose esters 0x ethers, but in these compounds the high contents cf residual solvents is objectionable. I prefer to mold my improved spool from the phenol formaldehyde resins currently known as bakellte, which fumish a tough and ineitpensive spool that will present a. smooth surfa.ce und 'which contain a. low residual solvent content. 'Ihis content should be furlgher reduced by seasoning for several months or by an accelerated seasoning process which comprises heating the molded spool for approximately four hours et a, temperature 01' approximately 160 F.

An lmproved construction is exempllfled in the drawlng whereln the sfibol 12 comprises an integrally molded outer annular portlon 13 und 1nner annular portion 14 jolned by a. median web 18 a.nd reinforced by a.xial longitudinal ribs 15. 35 An integral key 16 is also ca.st in the bore 19 01 the spool 12, extending axially along the bore 19 end positioned to coincide with one of the longitudinal relnforcing ribs '15, o1 preferably with an enlarged rib 17, designed to further strengthen the key und to protect it from damage due to accidental blows- The bore 19, und the key 16, a.re designed to aecmmodate the usual adapters for engaging spindles in the usual camera magezxnes.

Further study lead to the determination o1 the most economical ratio between the diameter o1" the spool 12 end the thickness 01 the film 10 wrapped thereon. II a spool is too small in dlameter lt imparta a bad curl to the center sectiorf of the roll 01 film, and if the spool is too large it unnecessarily and uneconomically increases the weight and bulk of the film package and reduces the film footage it is possible to use in the camera magazine. I have found that for economical curlprevention the preferable ratio between the diameter of the spool and the thickness 01 the finished coated film should. be in the proportion ranging from approximately 360 to 1 for some types of positive film, to 300 to 1 for some types of negative film which affords a preferred avera.ge ratio of approximately 330 to 1.

Another disadvantage present in the o1d wooden spools that were equipped with a surface slot for engaging the end of the film to be wound thereon arose from the fact that a hump was formed over the point where the and o f the film entered the slot in the spool. This hump caused the whole reel to become out of round, and in sound recording work this presented a serious defect that resulted in the abandonment of the slot. It was attempted to hold the end of the film 0n the wooden spool with a piece of adhesive tape, but it was found that the adhesive pulled the surface splinters from the wood and hence added to the foreign matter present in the film package. It was also attempted to use the adhesive strip on the metal spool, but it was found that the combination of various ingredients in the adhesive and in the metal surface increased the tendency to photographically Iog the film. With my improved molded spool 12, these disadvantages are also overcome and the Cameraman may employ the strip of adhesive 11, which not only permits the film 10 to be held on the spooi 12 without contamination on undue distortion but also is of assistance in re-winding or back-winding operations, in loadii1g, unioading and for various adjustments of the film in the camera magazine, all of which are extremely desirable and helpful to cameramen. The smooth surface ot my improved spool afiords such complete coutact with the surface of the film that in packing the film at the factory it is not necessary to use the adhesive 11 as the surface contact affords sufficient bite for the film to grip the spool after a minimum number of convolutions thereon An added advantage 1s obtained by using spools of various bright colors to indicate various types of film or sensitivities of emulsion thereon; for instanoe, a brilliant red spool may be used to indicate a film having an emulsion with high red sensitivity and a briliiant green spool may be 5 used to indicate high green sensitivityin a given partioular roll of negative film. The plastic compositions described herein can be produced in a vziriety of brilliant colors, which present a distinguishable indication even in a safe 1ight. 8

My invention is not limited to the particular embodiments shown and described herein its scope being set forth in my claims as followsz 1. In combination. a. curl-preventing, non-contaminating cinema reel for a cam era magazine 9 comprising a non-fogging, non-disintegrating smooth-surfaced, one piece seasoned spool, integrally molded from a phenol formaldehyde resin, and a roll of light-sensitive cellulose ester eine film wound thereon, the diameter 015 said 91 spool bearing a. ratio to the thickness 01 said film of approximately 330 to 1, said spool comprising an uninterrupted, smooth-surfaced, outer annular portion and an inner cored annular portion joined thereto by a median radial web and a plurality of longitudinal reinforcing ribs, one of which is positioned to reinforce a key axially extending along the bore of said inner annular portion.

2. In combination, a curl-preventing, non-contaminating cinema reel for a camera magazine comprising a non-fogging non-disintegrating, smooth-surfaced, one piece spool, integrally molded Irom an artificial resin product, and a roll of light-sensitive cellulose ester eine film wound thereon, the diameter of said spool bearing a ratio to the thickness 0f said film of approximately 330 to 1, said spool comprising an uninterrupted smooth-surfaced outer annular portion and an inner bored annular portion joined thereto by a median radial web and a plurality of longitudinal reinforcing ribs, one cf which is enlarged and positioned to reinforce a key axiallyextending along the bore of said inner annular portion said spool being colored to indicate a characteristic of said film.

DONALD H. KINLOCH. 

